US4496013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prevention of cone seal failures in rock bits
Assignee: Smith International Inc
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Filing: 1982-08-23
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Granted: 1985-01-29
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Expires: 2002-08-23
Abstract
Abstract There is provided a rock bit comprising a bit body having a dome and a plurality of legs, each with a journal pin. A cutter cone is mounted on each journal pin with a cone seal between the journal pin and cutter cone. A sacrificial anode is attached to the dome of the bit body having a shape for diverting flow of drilling mud around the cutter cones. Preferred shapes of the sacrificial anode include inverted cones and tetrahedrons. The sacrificial anode prevents cone seal failures caused by corrosion of the bit body adjacent the cone seals.
Inventors
- 👤 Richard E. Serpa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:56
CPC Classifications
E; E21; E21B; E21B41/00; E21B41/02; E21B10/00; E21B10/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
88 words
A rock bit for drilling subterranean formations comprising: a steel bit body including a dome and a plurality of legs, each leg having a journal pin; a cutter cone mounted on each journal pin; a cone seal at the base of each journal pin between the journal pin and cutter cone; and a sacrificial anode electrically connected to the dome of the bit body comprising a shape for diverting flow of drilling mud around the cutter cones, said anode being formed of a material less noble than steel.
Claim 2
Dependent Claim
88 words
A rock bit for drilling subterranean formations comprising: a steel bit body including a dome and a plurality of legs, each leg having a journal pin; a cutter cone mounted on each journal pin; a cone seal at the base of each journal pin between the journal pin and cutter cone; and a sacrificial anode electrically connected to the dome of the bit body comprising a shape for diverting flow of drilling mud around the cutter cones, said anode being formed of a material less noble than steel.
Claim 3
Dependent Claim
30 words
A rock bit as claimed in claim 1 wherein the sacrificial anode comprises metal selected from the group consisting of zinc, zinc alloys, magnesium, magnesium alloys, aluminum and aluminum alloys.
Claim 4
Dependent Claim
25 words
A rock bit as claimed in claim 1 wherein the sacrificial anode comprises a metal selected from the group consisting of zinc and zinc alloys.
Claim 5
Dependent Claim
46 words
A rock bit as claimed in claim 1 further comprising a threaded metal stud extending downwardly from the dome of the rock bit, generally normal to the dome, and the sacrificial anode comprises a threaded hole and wherein the sacrificial anode is threaded onto the stud.
Claim 6
Dependent Claim
17 words
A rock bit as claimed in claim 1 wherein the sacrificial anode comprises a generally tetrahedron shape.
Claim 7
Dependent Claim
15 words
A rock bit as claimed in claim 1 wherein the sacrificial anode is generally cone-shaped.
Claim 8
Dependent Claim
50 words
A rock bit as claimed in claim 1 further comprising an inverted metal receptacle attached to the dome of the bit body and in electrical contact with the bit body and into which the sacrificial anode is cast to thereby make electrical contact between the anode and the bit body.
Claim 9
Dependent Claim
20 words
A rock bit as claimed in claim 1 further comprising a permeable reinforcing network throughout the metal of the anode.
Claim 10
Dependent Claim
29 words
A rock bit as claimed in claim 4 further comprising a permeable protective cover over the sacrificial anode having greater resistance to erosion than the metal of the anode.
Claim 11
Dependent Claim
90 words
A rock bit for drilling subterranean formations comprising: a bit body including a dome and three legs, each leg having a journal pin; a cutter cone mounted on each journal pin; a cone seal at the base of each journal pin between the journal pin and cutter cone; and a sacrificial anode attached to the dome of the bit body and in electrical contact with the bit body comprising a metal less noble than the metal of the bit body and having a shape of an inverted cone or tetrahedron.
Claim 12
Dependent Claim
90 words
A rock bit for drilling subterranean formations comprising: a bit body including a dome and three legs, each leg having a journal pin; a cutter cone mounted on each journal pin; a cone seal at the base of each journal pin between the journal pin and cutter cone; and a sacrificial anode attached to the dome of the bit body and in electrical contact with the bit body comprising a metal less noble than the metal of the bit body and having a shape of an inverted cone or tetrahedron.
Claim 13
Dependent Claim
31 words
A rock bit as claimed in claim 10 wherein the sacrificial anode comprises a metal selected from the group consisting of zinc, zinc alloys, magnesium, magnesium alloys, aluminum and aluminum alloys.
Claim 14
Dependent Claim
25 words
A rock bit as claimed in claim 10 wherein the sacrificial anode comprises a metal selected from the group consisting of zinc and zinc alloys.
Claim 15
Dependent Claim
46 words
A rock bit as claimed in claim 10 further comprising a threaded metal stud extended downwardly from the dome of the rock bit generally normal to the dome, and the sacrificial anode comprises a threaded hole and wherein the sacrificial anode is threaded onto the stud.
Claim 16
Dependent Claim
50 words
A rock bit as claimed in claim 10 further comprising an inverted metal receptacle attached to the dome of the bit body and in electrical contact with the bit body and into which the sacrificial anode is cast to thereby provide electrical contact between the anode and the bit body.
Claim 17
Dependent Claim
20 words
A rock bit as claimed in claim 10 further comprising a permeable reinforcing network throughout the metal of the anode.
Claim 18
Dependent Claim
28 words
A rock bit as claimed in claim 10 further comprising a permeable protective cover over the anode having greater resistance to erosion than the metal of the anode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |